Vibration damper and preloader bearing assembly



United States Patent [72] Inventors Thomas S. Moore Dearborn; James T.Ross, Dearborn Heights, Mich. [21] Appl. No. 745,851 [22} Filed July 18,1968 [45] Patented Dec. 22, 1970 [73] Assignee Ford Motor CompanyDearborn, Mich. a corporation of Delaware [54] VIBRATION DAMPER ANDPRELOADER BEARING ASSEMBLY 13 Claims, 3 Drawing Figs.

[52] US. Cl. 280/96-1, 308/120 Primary Examiner-Kenneth H. BettsAttorney-John R. Faulkner and Clifford L. Sadler ABSTRACT: A bearingassembly that supports radial and thrust loads and which includes apreloaded elastomeric element providing torsional drag, shockabsorption, and vibration damping.

PATENTED M822 1970 29 I ILEEZ L I B a '4/ I 1 I44 I 1 -32 V I 34 /4THOMAS s MOORE JAMES T. ROSS INVENTORS i'; W BY WW.

ATTORNEYS VIBRATION DAMPER AND PRELOADER BEARING ASSEMBLY BACKGROUND OFTHE INVENTION Antifriction bearings that support thrust and radialimpact loads in addition to sustained loads experience continuouslyincreasing rates of wear during service. in certain applications suchwear causes undesirable vibrations, unsmooth operation, and eventuallystructural failure of the bearing assembly.

This invention provides a bearing assembly that supports both thrust andradial loads and which significantly reduces wear between bearingelements. The invention further provides a bearing assembly which istorsionally preloaded or has a torsional drag, absorbs impacts betweenthe bearing elements, and dampens vibrations transmitted to it. It alsoprovides a bearing assembly which is axially preloaded in a directiontending to oppose the general thrust support direction of the assembly.

Front-wheel-drive motor vehicles having solid front axles commonlyutilize a pair of stub kingpins to pivotally mount each steerable wheel.The kingpins, mounted to a steering knuckle, are often separated fromthe axle housing by a pair of tapered roller bearings. Substitution ofthe vibration damped and preloaded bearing assembly described herein forthe conventional tapered bearings results in substantially increasedbearing life, reduction in vibrations in worn bearing assemblies, andimproved vehicle riding and handling characteristics.

SUMMARY OF-TIIE INVENTION A vibration damped and preloaded antifrictionbearing assembly constructed in accordance with this invention includesfirst and second bearing races separated by a plurality of rollablebearing elements. A first member engages an axial end of the firstbearing race; a second member engages an axial end of the second bearingrace and encloses the first member. An elastomeric member is compressedbetween the first and second members. Upon movement of one bearing racerelative to the other, the first member rotates with the first bearingrace, while the second member rotates with the second bearing race.Relative movement occurs between the elastomeric member and either thefirst or second member.

BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF A PREFERREDEMBODIMENT In FIG. 1 of the drawings a portion ofa front axle housing isshown by a reference numeral 11. A steering knuckle 12 is pivotallyconnected to the axle housing by a pair of kingpin and bearingassemblies 13 and 14. A spindle 16 is secured to steering knuckle 12 bya series of capscrews 17. Also secured to knuckle 12 by the capscrews-17 is backing plate 18 of the vehicle front-wheel brakes. A portion ofa brakedrum is illustrated by reference numeral 19. Received withinspindle 16 and axle housing 11 are axle shafts 21 and 22, respectively,which are interconnected by universal joint 23. The pivotal axis of thesteering knuckle 12, about the axle housing 11, passes through thecenter of universal joint 23. A caged roller bearing 24 supports axleshaft 21 within the, spindle 16. Similarly, caged roller bearing 26supports axle shaft 22 within housing I 1.

A pair of coaxial bores 27 and 28 are formed in the arms of steeringknuckle l2. Bores 27 and 28 receive identical kingpin units 29. Thekingpin units 29 comprise flanged cap portions 31 and stepped diameterportions 32. The kingpin units 29 are coaxially secured to steeringknuckle'l2 by a number of capscrews 33. Tapered roller bearings arepress-fitted onto portions 32. Bearing 34 includes inner race 36, outerrace 37 and rollers 38. Stepped diameter portions 32 are formed withconvex ends 39, shown as hemispheres in F IG. 2. Hat-shaped, circulardisc members 41 engage sides of inner races 36 and receive the convexends 39 of portions 32 within their concave portions 42.

A pair of stepped bores 43 and 44 are formed in the yoke arms of axlehousing 11 into which outer races 37 of bearings 34 are press-fittedAlso received within stepped bores 43 and 44 and enclosing the ends 39of kingpin units 29 are caps 46. Caps 46 engage and move with outerraces 37 of bearings 34. Positioned between the discs 41 and the caps 46are elastomeric dampers 47. The dampers as installed are compressed asillustrated in FIG. 2. FIG. 3 illustrates a damper 47, in anuninstalled, undeformed state. In the preferred embodiment of theinvention, the damper has a thickness of approxi mately one-half inch, amaximum diameter of 1 inch, and is made of an urethane elastomer of adurometer hardness of on the A" scale. It is formed with a concaverecess'48 on one side. The convex end 39 of kingpin unit 29, the concaveportion 42 of hat-shaped disc 41 and the recess 48 of damper 47cooperate to keep disc 41 and damper 47 in substantial axial alignmentwith kingpin unit 29. Oil seals 49 are press-fitted into stepped bores43 and-44 and slidingly engage kingpin units 29.

A shim 51 may be positioned about kingpin unit 29 between the axlehousing 11 and the steering knuckle 12. In the preferred embodiment ofthe invention, a shim of a thickness sufficient to produce a torsionaldrag of 9 to 16 foot-pounds between the housing and the knuckle is used.

OPERATION The kingpin and bearing assemblies 13 and 14 provide a pivotalconnection between the front axle housing 11 and the steering knuckle12. The outer bearing race 37, cap 46, damper 47 and seal 49 remainfixed relative to the axle housing 11. The inner bearing race 36, disc41 and kingpin unit 29 remain fixed relative to and turn with steeringknuckle 12. Sliding movement thus occurs between the compressedelastomeric damper 47 and contoured disc 41. The friction between damper47 and disc 41 creates a torque drag or a torsional preloading to thebearing assembly. The magnitude of the torque drag may be varied bychanging the size or compression of the elastomeric damper.

The bearing assembly described above provides damping of both rotationaland axial vibrations as well as significantly increased impacttolerance.

The foregoing description presents a presently preferred embodiment ofthe invention. Modifications and alterations will occur to those skilledin the art that are included within the scope and spirit of thefollowing claims.

We claim:

1. A vibration damped and preloaded antifriction bearing assemblycomprising:

a first bearing race;

a second bearing race;

said races being separated by a plurality of bearing elements;

said races each having a first axial end surface facing in one directionand a second axial end surface facing in the opposite direction;

a first member engaging said first axial end surface of said firstbearing race;

a second member engaging said first axial end surface of said secondbearing race; and

a compressed elastomeric member received between said first member andsaid second member.

2. A bearing assembly according to claim 1 and including means to holdsaid races and said members in substantially fixed relative axialpositions.

'andfsaid second member enclosing said first memberand said elastomericmember. v i r r v 4. A bearing assembly according to claim 1 andincluding:

said secondr'nemberand theadjacent Contacting surface of f saidelastomeric memberbeing fixed in position relative to each otheruponmovement of one race relative to the a other; and

elementscomprising tapered roller elements;

'saidfirst member; and the adjacent contacting surfaceof saidvelastomeric surface being slidable relative touch 1 other upon movementof one race relative to the other.

i 5. A bearing assembly according to claim 1 and including the surfacearea of; saidfirst member in contact with said; elastomericmember beingless 'than the surface area of the second'member incontactwith saidelastomeric member. 1 6.A bearing assembly according to claim 1 andincluding;

said elastomeric member having a generally circular shape;

and

1 means toholdsaid members in substantially axial alignment withsaidbear ing races. 7. A bearing assembly according to claim 1 andincluding;

said firstand second bearing races comprising innercand outer bearingraces, respectively, said bearing elements comprising tapered rollerelements; and 7 said second memberand-the adjacent contacting surface ofI said elastomeric member being fixed in position relative toeachvotherupon move ment ofone race relative to the y I "other. 1: H 8. A bearingassembly according to claim 1 and including:

said elastomericjmember having a generally circular shape; means'to holdsaid members in substantially axial alignment with said bearing races;and v H means causing said elastomeric member to remain substantiallyfixed in said second memberupon angular displace ment of said secondbearing race. relative to said .first bearing racer 95A bearing assemblyaccording to claim 8 and including:

i said first and second bearing; races comprising inner and outerbearing races, respectively; and t 7 said bearing elements comprisingtapered roller elements. 10. Acombination kingpin and bearing assemblycomprising:

a kingpin member having an unattached end, end hav ing a convex shape; a

an inner bearingrace secured .to said kingpin member to move therewith;an outer bearing race; a

a plurality of tapered rollers separating said inner and outer I; j

a circular contoured. disc member having a convex portion 155 on onesideand a concave portionon the other side; said; concave portion-receivingthe convex'end of said kingpin bearing races;

e it a. said disc member engaging said inner race;

an elastomeric member having a concave indentation in one w side thatreceives the convex portion of said disc member; a cup member enclosingand compressing said elastomeric member-between said cup member and-saiddiscmember. I

and engaging said outer race; 1

means to holdsaid racesand said members in fixed axial positions;

said outer race being movable about said inner race, said cupmember-fixed relative to said outer race and movable therewith, saiddisc member fixed relative to said iriiter race and movable therewith;and

said, elastomeric member'm'ovable rella tive to said cup member uponangular displacement of said outer race V relativeto said inner race;

ll.v A pivotal; connection rorfa steering knuckle and axle housingassembly of a motoryehicle comprising:

a pair of kingpin and bearing assemblies according to claim l0coaxially. received in and interconnecting said steering knuckle andsaid axle housing; I I

one of said pair of assemblies being inverted relative to the each saidkingpin memberbeing secured to said steering knuckle and movabletherewith; and t r each said outer race being secured to said axlehousing.

12. A pivotal connection for asteenng knuckle and axle housing assemblyof a motor vehicle including:

a pair of kingpin and bearing assemblies, each of said .pair comprisinga 'kingpin member having an unattached end;

a first bearingrace secured to said'kingpin member to move therewith; g

a secondbearing race, said races b'eing separated by a plurality ofbearing elements; t I

a first memberfengaging an axial end of said first bearing race;" a r asecond member engaging an axial end of said second bearing race andenclosing said first member;

' one of said pair of assemblies being inverted relative to the t other.t 13. A pivotal connection. fora steering knuckle and axle housingassembly of a motor vehicle including;

a pair of kingpin and bearing assemblies, each of said pair comprising akingpin member having an unattached end;

a first bearing race secured to said kingpin member to move therewith; i

a second bearing race, said races being separated by a plurality ofbearing elements;

a first member engaging an axial end of said first bearing race; t

a second member engaging an axial end of said second bearing race andenclosing-said first member;

a compressed elastomeric memberreceived between saidt'ust memberandsaidfsecondmember, and said pair'of kingpin and'bearing assembliesbeing coaxially received in and interconnecting said steering knuckleand said axle housing.

a comp essed elastomericf member received between said

